var AnimateStar = {};
var canvas;
var num = 40;
// var w = window.innerWidth;//by itdos
var w = 240;
var h = window.innerHeight;
var max = 40;
var _x = 0;
var _y = 0;
var _z = 150;
var dtr = function (d) {
  return (d * Math.PI) / 180;
};

var rnd = function () {
  return Math.sin((Math.floor(Math.random() * 360) * Math.PI) / 180);
};
var dist = function (p1, p2, p3) {
  return Math.sqrt(Math.pow(p2.x - p1.x, 2) + Math.pow(p2.y - p1.y, 2) + Math.pow(p2.z - p1.z, 2));
};

var cam = {
  obj: {
    x: _x,
    y: _y,
    z: _z
  },
  dest: {
    x: 0,
    y: 0,
    z: 1
  },
  dist: {
    x: 0,
    y: 0,
    z: 200
  },
  ang: {
    cplane: 0,
    splane: 0,
    ctheta: 0,
    stheta: 0
  },
  zoom: 1,
  disp: {
    x: w / 2,
    y: h / 2,
    z: 0
  },
  upd: function () {
    cam.dist.x = cam.dest.x - cam.obj.x;
    cam.dist.y = cam.dest.y - cam.obj.y;
    cam.dist.z = cam.dest.z - cam.obj.z;
    cam.ang.cplane = -cam.dist.z / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z);
    cam.ang.splane = cam.dist.x / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z);
    cam.ang.ctheta = Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.z * cam.dist.z) / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.y * cam.dist.y + cam.dist.z * cam.dist.z);
    cam.ang.stheta = -cam.dist.y / Math.sqrt(cam.dist.x * cam.dist.x + cam.dist.y * cam.dist.y + cam.dist.z * cam.dist.z);
  }
};

var trans = {
  parts: {
    sz: function (p, sz) {
      return {
        x: p.x * sz.x,
        y: p.y * sz.y,
        z: p.z * sz.z
      };
    },
    rot: {
      x: function (p, rot) {
        return {
          x: p.x,
          y: p.y * Math.cos(dtr(rot.x)) - p.z * Math.sin(dtr(rot.x)),
          z: p.y * Math.sin(dtr(rot.x)) + p.z * Math.cos(dtr(rot.x))
        };
      },
      y: function (p, rot) {
        return {
          x: p.x * Math.cos(dtr(rot.y)) + p.z * Math.sin(dtr(rot.y)),
          y: p.y,
          z: -p.x * Math.sin(dtr(rot.y)) + p.z * Math.cos(dtr(rot.y))
        };
      },
      z: function (p, rot) {
        return {
          x: p.x * Math.cos(dtr(rot.z)) - p.y * Math.sin(dtr(rot.z)),
          y: p.x * Math.sin(dtr(rot.z)) + p.y * Math.cos(dtr(rot.z)),
          z: p.z
        };
      }
    },
    pos: function (p, pos) {
      return {
        x: p.x + pos.x,
        y: p.y + pos.y,
        z: p.z + pos.z
      };
    }
  },
  pov: {
    plane: function (p) {
      return {
        x: p.x * cam.ang.cplane + p.z * cam.ang.splane,
        y: p.y,
        z: p.x * -cam.ang.splane + p.z * cam.ang.cplane
      };
    },
    theta: function (p) {
      return {
        x: p.x,
        y: p.y * cam.ang.ctheta - p.z * cam.ang.stheta,
        z: p.y * cam.ang.stheta + p.z * cam.ang.ctheta
      };
    },
    set: function (p) {
      return {
        x: p.x - cam.obj.x,
        y: p.y - cam.obj.y,
        z: p.z - cam.obj.z
      };
    }
  },
  persp: function (p) {
    return {
      x: ((p.x * cam.dist.z) / p.z) * cam.zoom,
      y: ((p.y * cam.dist.z) / p.z) * cam.zoom,
      z: p.z * cam.zoom,
      p: cam.dist.z / p.z
    };
  },
  disp: function (p, disp) {
    return {
      x: p.x + disp.x,
      y: -p.y + disp.y,
      z: p.z + disp.z,
      p: p.p
    };
  },
  steps: function (_obj_, sz, rot, pos, disp) {
    var _args = trans.parts.sz(_obj_, sz);
    _args = trans.parts.rot.x(_args, rot);
    _args = trans.parts.rot.y(_args, rot);
    _args = trans.parts.rot.z(_args, rot);
    _args = trans.parts.pos(_args, pos);
    _args = trans.pov.plane(_args);
    _args = trans.pov.theta(_args);
    _args = trans.pov.set(_args);
    _args = trans.persp(_args);
    _args = trans.disp(_args, disp);
    return _args;
  }
};

(function () {
  "use strict";
  var threeD = function (param) {
    this.transIn = {};
    this.transOut = {};
    this.transIn.vtx = param.vtx;
    this.transIn.sz = param.sz;
    this.transIn.rot = param.rot;
    this.transIn.pos = param.pos;
  };

  threeD.prototype.vupd = function () {
    this.transOut = trans.steps(this.transIn.vtx, this.transIn.sz, this.transIn.rot, this.transIn.pos, cam.disp);
  };

  var Build = function () {
    this.vel = 0.04;
    this.lim = 360;
    this.diff = 200;
    this.initPos = 100;
    this.toX = _x;
    this.toY = _y;
    this.go();
  };

  Build.prototype.go = function () {
    canvas = document.getElementById("canv");
    if (canvas == null) {
      // by itdos
      return;
    }
    // canvas.width = window.innerWidth;
    canvas.height = window.innerHeight;
    this.$ = canv.getContext("2d");
    this.$.globalCompositeOperation = "source-over";
    this.varr = [];
    this.dist = [];
    this.calc = [];

    for (var i = 0, len = num; i < len; i++) {
      this.add();
    }

    this.rotObj = {
      x: 0,
      y: 0,
      z: 0
    };
    this.objSz = {
      x: w / 5,
      y: h / 5,
      z: w / 5
    };
  };

  Build.prototype.add = function () {
    if (this.varr.length < max) {
      //by itdos
      this.varr.push(
        new threeD({
          vtx: {
            x: rnd(),
            y: rnd(),
            z: rnd()
          },
          sz: {
            x: 0,
            y: 0,
            z: 0
          },
          rot: {
            x: 20,
            y: -20,
            z: 0
          },
          pos: {
            x: this.diff * Math.sin((360 * Math.random() * Math.PI) / 180),
            y: this.diff * Math.sin((360 * Math.random() * Math.PI) / 180),
            z: this.diff * Math.sin((360 * Math.random() * Math.PI) / 180)
          }
        })
      );
      this.calc.push({
        x: 360 * Math.random(),
        y: 360 * Math.random(),
        z: 360 * Math.random()
      });
    }
  };

  Build.prototype.upd = function () {
    cam.obj.x += (this.toX - cam.obj.x) * 0.05;
    cam.obj.y += (this.toY - cam.obj.y) * 0.05;
  };

  Build.prototype.draw = function () {
    this.$.clearRect(0, 0, canvas.width, canvas.height);
    cam.upd();
    this.rotObj.x += 0.1;
    this.rotObj.y += 0.1;
    this.rotObj.z += 0.1;

    for (var i = 0; i < this.varr.length; i++) {
      for (var val in this.calc[i]) {
        if (this.calc[i].hasOwnProperty(val)) {
          this.calc[i][val] += this.vel;
          if (this.calc[i][val] > this.lim) this.calc[i][val] = 0;
        }
      }

      this.varr[i].transIn.pos = {
        x: this.diff * Math.cos((this.calc[i].x * Math.PI) / 180),
        y: this.diff * Math.sin((this.calc[i].y * Math.PI) / 180),
        z: this.diff * Math.sin((this.calc[i].z * Math.PI) / 180)
      };
      this.varr[i].transIn.rot = this.rotObj;
      this.varr[i].transIn.sz = this.objSz;
      this.varr[i].vupd();
      if (this.varr[i].transOut.p < 0) continue;
      var g = this.$.createRadialGradient(this.varr[i].transOut.x, this.varr[i].transOut.y, this.varr[i].transOut.p, this.varr[i].transOut.x, this.varr[i].transOut.y, this.varr[i].transOut.p * 2);
      this.$.globalCompositeOperation = "lighter";
      g.addColorStop(0, "hsla(255, 255%, 255%, 1)");
      g.addColorStop(0.5, "hsla(" + (i + 2) + ",85%, 40%,1)");
      g.addColorStop(1, "hsla(" + i + ",85%, 40%,.5)");
      this.$.fillStyle = g;
      this.$.beginPath();
      this.$.arc(this.varr[i].transOut.x, this.varr[i].transOut.y, this.varr[i].transOut.p * 2, 0, Math.PI * 2, false);
      this.$.fill();
      this.$.closePath();
    }
  };
  Build.prototype.anim = function () {
    window.requestAnimationFrame = (function () {
      return (
        window.requestAnimationFrame ||
        function (callback, element) {
          window.setTimeout(callback, 1000 / 60);
        }
      );
    })();
    var anim = function () {
      this.upd();
      this.draw();
      window.requestAnimationFrame(anim);
    }.bind(this);
    window.requestAnimationFrame(anim);
  };

  Build.prototype.run = function () {
    this.anim();

    window.addEventListener(
      "mousemove",
      function (e) {
        this.toX = (e.clientX - canvas.width / 2) * -0.8;
        this.toY = (e.clientY - canvas.height / 2) * 0.8;
      }.bind(this)
    );
    //by itdos 注释
    // window.addEventListener('touchmove', function (e) {
    //     e.preventDefault();
    //     this.toX = (e.touches[0].clientX - canvas.width / 2) * -0.8;
    //     this.toY = (e.touches[0].clientY - canvas.height / 2) * 0.8;
    // }.bind(this));
    // window.addEventListener('mousedown', function (e) {
    //     for (var i = 0; i < 100; i++) {
    //         this.add();
    //     }
    // }.bind(this));
    // window.addEventListener('touchstart', function (e) {
    //     e.preventDefault();
    //     for (var i = 0; i < 100; i++) {
    //         this.add();
    //     }
    // }.bind(this));
    window.addEventListener(
      "resize",
      function () {
        // canvas.width = w = window.innerWidth; //by itdos
        canvas.height = h = window.innerHeight;
      },
      false
    );
  };
  // var app = new Build();
  // app.run();
  //by itdos
  // AnimateStar = new Build();
  AnimateStar = Build;
})();

export { AnimateStar };
